3D-Printed Biohybrid PE/PCL Biphasic Osteochondral Plug for Knee Cartilage Repair

Biohybrid polyethylene (PE) and polycaprolactone (PCL) were used to regenerate cartilage and bone tissues for repair of knee joint defects. Biohybrid polyethylene was synthesized using ring-opening metathesis polymerization methods with polyethylene-containing macromonomer and arginylglycylaspartic acid (RGD), laminin-derived peptide A5G81 (AGQWHRVSVRWG), or hyaluronic acid-containing macromonomer. The resultant brush copolymers were formulated with ultrahigh molecular weight polyethylene to create formulations for testing with human chondrocyte assays. PE-RGD formulation was determined to be the most effective in causing statistically significant chondrocyte proliferation consistently. PCL-RGD was used to create the stem of the plug for osteogenesis. The materials were 3D printed using dual nozzle fused filament fabrication method to create a biphasic interlocking plug for <i>in vivo</i> testing of cartilage and bone regeneration in porcine knee joint defect models. The studies provide a guide for fabrication of cartilage repair implants using biohybrid polymers.